DisplayMetric Class Reference

#include "stage/model/canvas-hook.hpp"

Description

Mix-in interface to allow for concrete CanvasHooked widgets to adapt themselves to the metric currently employed on the canvas.

In some cases, most notably when a timeline canvas is calibrated to precisely represent temporal extension, the widgets (clips, effects) within such a display need to adjust and adapt themselves. A relevant case is when such a widget is dragged — receiving mouse move events in screen coordinates — which then should be translated into a resulting temporal offset or change command to reflect this interaction gesture.

Definition at line 73 of file canvas-hook.hpp.

Public Member Functions
virtual	~DisplayMetric ()
	this is an interface
virtual TimeSpan	coveredTime () const =0
	the overall time Duration covered by this timeline canvas
virtual int	translateTimeToPixels (TimeValue) const =0
	extension point for time axis zoom management.
virtual int	translateScreenDelta (Offset) const =0
	translate a temporal offset into a pixel Δ
virtual TimeValue	applyScreenDelta (Time anchor, double deltaPx) const =0
	translate an offset in pixel coordinates into a temporal position

Constructor & Destructor Documentation

~DisplayMetric()

virtual ~DisplayMetric ( )

inlinevirtual

this is an interface

Definition at line 76 of file canvas-hook.hpp.

Member Function Documentation

coveredTime()

virtual TimeSpan coveredTime ( ) const

pure virtual

the overall time Duration covered by this timeline canvas

Referenced by DisplayManager::getPixSpan().

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translateTimeToPixels()

virtual int translateTimeToPixels ( TimeValue  ) const

pure virtual

extension point for time axis zoom management.

Referenced by DisplayManager::getPixSpan().

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translateScreenDelta()

virtual int translateScreenDelta ( Offset  ) const

pure virtual

translate a temporal offset into a pixel Δ

applyScreenDelta()

virtual TimeValue applyScreenDelta ( Time  anchor, double  deltaPx  ) const

pure virtual

translate an offset in pixel coordinates into a temporal position

Parameters

anchor	the start point on the time axis where to apply the delta
deltaPx	a delta given as canvas pixel displacement

Returns

resulting TimeValue when applying the offset within current metric

Referenced by ClipPresenter::DragRelocateObserver::updateOffset().

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Inheritance diagram for DisplayMetric:

Collaboration diagram for DisplayMetric:

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The documentation for this class was generated from the following file:

• canvas-hook.hpp